Radio base stations used in radio communications, e.g., cellular, WiFi, etc., are programmable or configurable and include control electronics. Base stations also typically use software programs executed by a computer along with reconfigurable hardware like Field Programmable Gate Arrays (FPGAs). Base stations can often operate in more than one mode and/or support more than one type of radio access technology, e.g., radio circuits dedicated for GSM and LTE modulations. As a result, base stations may be flexibly and generically designed so that they can later be tailored for a specific environment, technology, mode of operation, etc. This is the case for radio base station (RBS) “connectors.”
RBS connectors are used for interconnecting parts of the base station, sometimes referred to as RBS sub-units, connecting the base station to other node(s) in the cellular system over a transport network, and/or connecting/controlling local equipment like climate systems, burglar alarms, and backup power. The connectors are often “generic” in that they are (re)configurable. A generic connector can be (re)configured using software or hardware. A software example is an Ethernet connector that allows connection with a base station service engineer's laptop or with Radio Network Controller (RNC). The connector and the Ethernet chip do not change, but the specific configuration of software and/or settings in the base station and the device being connected to the base station determines whether the base station and that device are compatible to connect or not. A base station connector may also be associated with programmable hardware, for example, connector circuits that may change between ATM-STM-1 mode and Ethernet according to RBS software and/or settings. Such hardware circuits may also be combined using an adapter plug that changes the properties of the physical connector. Small Form-factor Pluggable (SFP) is one known standard adapter allowing electrical and optical cables to be connected to an SFP slot using a suitable SFP adapter module. In any event, a generic RBS connector is made specific by programming/configuring it for a specific use. Non-limiting examples of specific base station connectors and/or connectors on base station sub units include power supplies (with specified voltage and/or current properties), antenna connectors (with requirements to connect the proper antennas to achieve intended radio coverage and performance), radio connectors that are used for example in accordance with the CPRI standard to connect baseband unit(s) to radio units, and an RBS interconnect that couples clock signals, data signals, and control signals between (sub)units in large RBSs.
But this flexible RBS connector configuration can lead to errors. For example, a base station site engineer must consult several sources in order to learn where a cable is to be connected in a generic base station if there is no indication as to what that connector is currently programmed to do. So if a base station is generically configured when it is initially put into service, and then reprogrammed by the system into a special operation or role, there is no way for the site engineer to know, without consulting a secondary source: (1) how the base station is currently configured, (2) if the base station is configured as expected, and (3) what connectors to connect. Generically-configured base station units also increase the risk for human errors in a repair context because it may be difficult for a repair person to examine a base station unit and immediately see its current configuration. Without an easily-readable indicator that a base station unit is faulty, there is a risk that faulty and working base station units are mixed by mistake.
Consider a base station power supply unit with a configurable maximum current where it is desirable to have that maximum current visible on the unit. It is possible to simply print the fixed maximum current directly on the unit, but this is not a good option for a configurable unit where the maximum current may be reconfigured to a different value. While a powered display attached to or near the unit could be used to display the currently-configured maximum current, it would be beneficial to provide that same information to a human in a non-volatile way, i.e., where the current value is readable even when power is off, without either physically updating, e.g., by replacing or printing, the overlay or by adding some kind of battery backup.
Another example is where an operator has a radio base station with a 20 W transmitter for which it is possible to upgrade the base station to an 80 W transmitter. In order to support the upgrade, the maximum current to the transmitter must also be increased. Even though the entire base station upgrade operation can be performed remotely, there is no visible indication on the transmitter and power unit of the upgraded base station of the increased power and current.
One way of increasing flexibility of generically-configured base station units while at the same time guiding human operators regarding specific configurations for base station connectors and informing repair personnel is through the use of overlays. An overlay is printed text and/or symbols around a human input or output indicator like connectors, lamps, displays, knobs, and buttons on the base station, typically on a base station console. An overlay helps a human to identify the use for a human input or output and to interpret the status of the base station such as identifying which connector to plug in, which button to push, etc. An overlay is typically a printed paper or clear sheet mounted on the base station console or panel with text/symbols printed thereon or text/symbols may be printed directly on the console or panel.
Unfortunately, traditional overlay approaches require updating or changing the overlay for a base station unit, and thus, require some sort of mechanical work and/or manufacturing to provide a new overlay. For example, if a base station is reconfigured using software, the old, out-of-date overlay (text/images) for the old software configuration remains until someone prints a new overlay and physically mounts it on the base station. This is a significant disadvantage when the radio base station is located 500 km away and is operated remotely. In this case, even if the update or change of the base station can be performed over a data connection from a control center, that does not change the printed text on the overlay(s) on that base station.